1. Field of the Invention
This invention relates to techniques for propagating magnetic single wall (bubble) domains and, more particularly, to field access propagation techniques for high magnetization bubble domain materials.
2. Description of the Prior Art
Typical presently used magnetic rare earth garnet materials provide bubble domains having diameter, at collapse, of about 2-6 microns. To achieve greater efficiency in the use of bubble domains to store and transfer information, bubble domain materials, such as amorphous GdCo and magnetic rare earth garnets, have been developed that can support bubble domains having a relatively small, even submicron, collapse diameter. However, the magnetization of such bubble domain materials is high (on the order of several thousand oersteds) compared to the magnetization (about 200 oersteds) of previous garnet bubble domain materials. As a result, the magnetic field produced by the bubble domains is increased and exerts a correspondingly greater polarizing effect on the poles of propagation elements, such as Y-bars and T-bars.
A high, in-plane drive field is required to overcome the increased polarization of propagation elements and move the bubble domains formed in the high magnetization material. The high drive field requirement makes the design of the associated drive coils and electronics extremely difficult. It may thus be appreciated that it is desirable to have a technique for reducing the polarizing effect of high magnetization bubble domain materials.